Process for treating complex cobalt ores and for refining cobalt from nickel, arsenical, and silver-bearing ores.



No. 881,527. PATENTED MAR. 10, 1908. E. E. ARMSTRONG. PROCESS FOR TREATING COMPLEX COBALT ORES AND FOR REFINING COBALT FROM NICKEL, ARSENIGAL, AND SILVER BEARING ORES APPLICATION FILED MAY 1, 1906.

IMJ I l l l l I Witnesses (Juuantoz UNITED STATES PATENT OFFICE.

ERNEST E. ARMSTRONG, OF NIAGARA FALLS, NEW YORK.

PROCESS FOR TREATIN COMPLEX COBALT ORES AND FOR REFINING COBALT FROM NICKEL, ARSENIGAL, AND SILVER-BEARING ORES.

Specification of Letters Patent.

Application filed Mayl, 1906. Serial No. 814,624.

Patented March 10, 1908.

To all whom it may concern:

Be it known that I, ERNEST E. ARM- STRONG, a citizen of Canada, and a resident of Niagara Falls, county of Niagara, and

State of New York, have invented a new and useful Process for Treating Com lex Cobalt Ores and for Refining Cobalt f fom Nickel, Arsenical, and Silver-Bearing Ores, of which the following is a specification.

This process is particularly useful for treating the mixed ores of the Temiskaming or Cobalt Lake district, and in describin my process I will take of the typical mixed ore of that district the average run of material that would be supplied to a smelter as an example. that the process'involved may be applied broadly to many ores of more or less similar character by such slight modifications to meet the particular ore as will suggest themselves. Certain portions of my process may also be applied broadly to the refining of cobalt from impure cobalt solutions of whatever source.

The ore that will be taken as an example of the preferred treatment contains silver cobalt, usually nickel, arsenic, sulfur and more or less iron and sometimes antimony. The economic problem is to extract the silver and noble metals, nickel and cobalt, economically on a large scale and incidentally to extract also the arsenic, either as metal or a useful salt.

In the accompanying drawing, I have shown in vertical section the cell that I prefer to use for the electrolysis of the cobalt solution. a

The following is adesciiption in three steps of the preferred form of my process. It is to be understood, however, that I do not limit myself to the details of these steps nor to the use of all of the steps since I am aware that certain of the steps may be usefully applied to certain materials without the others and with considerable modification in details.

The first step consists in making asolution of the cobalt attended with such iron and nickel, if any, as may be present in the ore. I first roast the ore and thereby remove a large portion of the arsenic which can be collected in a suitable apparatus, as a White oxid of arsenic As,,O and saved. Durin the roasting, a large part of the sulfur, i present, is converted into sulfur It will be apparent, however,

dioxid SO which, if desired, can be further converted into sulfuric acid. I next smelt the calcined ore with proper fluxes in a cupola or reverberatory furnace and bessemerize the resulting matte to remove the excess of iron. matte preferably with nitrate or carbonate of. soda,'to further remove the arsenic and sulfur. I next mix' the calcined product with charcoal, retort coke, or other form of carbon and smelt it in a crucible or reverberatory furnace, and cast it-into ano des. I next electrolyze these anodes in an acid bath and continue the operation till the acid of the bath is saturated with the iron, cobalt and nickel. Durin this electrolysis, silver, gold, platinum and other precious metals separate fromthe anodes as slimes and fall to the bottom of the vat and can be collected and refined by any of the well known methods used for that purpose. The acid of this bath is preferably sulfuric or hydrochloric but may be sulfate of soda or an organic acid, such as acetic, citric, tartaric or oxalic.

The second step is to separate the iron from the solution produced 1n the first step. For this purpose, said solution is placed as the electrolyte in the cell shown in the accompanying drawing, which will be more particularly described below. ThlS cell has msoluble electrodes preferably of graphite; the positive electrode or anode being placed near the bottom of the cell and the negative or cathode above, as near as possible to the top of the electrolyte. The cathode 1s mcased in a porous inclosure or other form of diaphragm, to prevent the hydrogen from combining with the electrolyte and neutralizing the oxidizing effect of the gases liberated at the anode.

Before or during this electrolysis, I add to the said solution forming the electrolyte, a chlorid of an alkali or alkaline earth, preferabl chlorid of sodium. The nascent chlorin generated imthe electrolyte at the anode oxidizes the iron in the solution to the ferric conditioin In lieu of the chlorid, another halogen salt of a metal, such as a bromid, a fiuorid or an iodid, may be employed. The complete oxidation of the iron can be determined by testing a sample of the solution with potassium ferro cyanld and otassium ferri cyanid. The electrolysis is then stopped and the solution I next grind and calcine the drawn ofi into precipitating tanks. Milk of lime or the caustic soda from the cathode cipitated as oxid of cobalt which can then be removed by settling or filtering and the .nickel can then be precipitated and separated in the same manner. Or the cobalt and nickel can be simultaneously recipitated as sesquioxids, the caustic so a generated in the cathode compartment being used to assist in the precipitation.

The electrolytic cel shown in the accomanying drawing, may be described as ollows: M is a wooden tank lined with asphalt or other acid resisting paint. A, A, are raphite conductors carrying the current to t e positive electrodes H, H, situated at the bottom of the tank. B ,is a graphite conductor carrying the current from the negative electrode G. C is a frame supporting the diaphragm which incloses the negative electrode. D and E are'two perforated hard rubber baskets; the basket E being placed within the larger basket D and the space between the two baskets bein filled with asbestos fiber F or ground grap 'te or other suitable material to form a orous medium between the walls of the per orated baskets to act as a porous diaphragm. In order to prevent the hydrogen from the cathode passing through the porous cell into the anode compartment I, the solution in the anode compartment is maintained slightly higher than the solution in the cathode compartment J causing a slight flow of the liquid through the diaphragm toward the cathode. Having thus described my invention, I

claim as new and desire to secure by Letters Patent:

1. The-process. of separating cobalt which consists in electro chemically precipitating the cobalt as oxid by treating a solution of the same to electrolysis in the presence of a halogen salt of a metal.

2. The process of separating cobalt which Y consists in electro chemically precipitatin the cobalt as oxid by treating'a solution 0 the same to electrolysis in the presence of a chlorid.

3. The process'of separating cobalt which consists in electro chemically precipitating the cobalt as 'oxid by treating a solution of the same to electrolysis by an electrode which is not soluble in the electrol te in the presence of a halogen salt of a meta 4. In the process of refining cobalt solution containing iron, the steps which consist in treating a solution of the same to electrolysis in the presence of a halogen salt of a metal until the iron is converted into the ferric state and precipitating the iron compound. 7

5. The process of separating cobalt which consists in electro chemically precipitating the cobalt as oxid by treating the same to electrolysis in the presence of a halogen salt of a metal until the iron is converted into the ferric'state, interrupting the electrolysis, precipitating the iron compound, and then continuing the electrolysis until the cobalt is electrochemically precipitated as oxid.

6. The process of separating cobalt which consists in the electrolysis of a solution of the same-in the presence of a halogen salt of a metal until the iron is converted to the ferric state, interrupting the electrolysis, preci itating the iron com ound and continuin t 1e electrolysis until t e cobalt and nicke are precipitated? 7. The process of treating com lex cobalt ore which consists in removin t e bulk of such arsenic and sulfuras may e present by calcinin and smelting, forming into an anode, issolving the anode thus produced in an acid electrolyte, electrolyzin the solution in the presence of a halogen sa '0 of a metal until the iron is separated andfurther electrolyzin the solution until the cobalt is precipitate 8. The rocess of treating cobalt ores which consists in formin the same into an anode, dissolving the ano e thus'produced in an acid electrolyte, electrolyzing the solution in the presence of a halo on salt of a metal until the iron is converte to the ferricstate, separating the iron, and further ele'ctrolyzing the solution until the cobalt is preci itated.

- In testimony whereof, I have ereunto signed my name in the presence of two subscribing witnesses. j

ERNEST E. ARMSTRONG.

Witnesses:

- WM. J. SIRDEVAN, ARTHUR KILLIAN. 

